The Third Generation Partnership Project (3GPP) specifications define a mechanism that provides signaling integrity for SIP (session initiation protocol) signaling between the IP multimedia subsystem (IMS) (P-CSCF) and the user equipment (UE). Signaling integrity prevents identity spoofing, man-in-the-middle attacks, etc.
The IMS represents a 3GPP and 3GPP2 effort to define an all-IP based wireless network as a replacement for the disparate voice, data, signaling, and control network elements, and enables the support for IP multimedia applications within the UMTS (Universal Mobile Telecommunications System). The UMTS is a 3G broadband packet-based transmission of text, digitized voice, video, and multimedia that offers a consistent set of services to mobile computer and phone users no matter where they are located in the world.
The telecom industry is currently shifting towards all-IP systems, driven by the fundamental need to reduce costs, create new revenue generating services and to protect the operator business model, and IMS is a new core and service domain that enables the convergence of data, speech and network technology over an IP-based infrastructure. It is the operator choice of control and service logic for IP packet-based communication. For users, IMS-based services enable communications in a variety of modes that include voice, text, pictures and video, or any combination thereof in a highly personalized and secure way. IMS is designed to fill the gap between the existing traditional telecommunications technology and Internet technology that increased bandwidth alone does not provide, and allows operators to offer new, innovative services that share holders and end users are expecting.
In release 5 of the 3GPP specifications, the IMS has been specified to be access independent. This means that the access technology used to transport user SIP messages to the IMS network does not impact the functionality of the IMS network itself. Consequently, any access can be used such as DSL (digital subscriber line), cable modem, WLAN (wireless LAN), and GPRS (general packet radio service), for example. Access independence supports major efforts to converge network architectures.